Developer tool
API Tester
Generate curl commands to test APIs in your browser. Enter an endpoint and HTTP method, and the tool produces a ready-to-run request you can paste into your terminal.
Everything is generated locally on your device — your endpoints are never sent anywhere.
Privacy & data handling
Browser processingThis tool processes your input locally in your browser. Nothing is uploaded to a server or sent to an external service.
Interactive tool
API Tester
• Direct Browser Mode: Dispatches requests directly from your device. Ideal for local dev servers (http://localhost:3000) and public APIs that support CORS headers.
• Server Relay Mode: Proxies the HTTP request server-to-server via ToolKitHub backend without browser CORS limitations.
Overview
What does API Tester do?
This tool assembles curl commands from the details you provide: the API endpoint, the HTTP method, and an optional JSON body. It generates a command you can run in your terminal — the tool itself does not send requests. URL and the HTTP method (GET, POST, PUT, DELETE, and others). The output is a complete curl command with a JSON content-type header, ready to run in your terminal.
It is a command builder, not a live request runner: the tool produces the command, and you execute it wherever you need to — your local machine, a container, or a CI job. That makes it useful for documentation, sharing requests with teammates, and scripting.
The generated command follows standard curl conventions, so it works in any environment where curl is installed.
Under the hood
How does it work?
The tool reads the first line of your input as the endpoint URL and the second line as the HTTP method. It then assembles a curl invocation: the method flag, the URL, and a JSON content-type header.
The command is built by simple string assembly in the browser — no request is made to any server, and your endpoint never leaves your device.
The result is shown as text you can copy straight into a terminal.
Key features
Features of API Tester
Use cases
When should you use API Tester?
Quick endpoint tests
Generate a curl command to hit an endpoint and confirm it responds as expected.
Documentation examples
Include ready-to-run curl examples in API documentation.
Sharing with teammates
Send a teammate an exact request to reproduce an issue or verify a fix.
Scripting and automation
Generate commands to drop into scripts and CI pipelines.
Step-by-step
How to use API Tester
- Step 1
Enter your API endpoint URL.
- Step 2
Select the HTTP method and add headers/body.
- Step 3
Copy the generated curl command.
Real example
Example
Your input
https://api.example.com/users POST
Generated command
curl -X POST https://api.example.com/users -H "Content-Type: application/json"
The output is a complete curl command ready to paste into a terminal.
Technical information
How the details work
curl is the standard command-line tool for transferring data with URLs, and it is the de facto way to test HTTP APIs from the terminal. A basic request needs the URL, the method (-X), and often headers (-H) like Content-Type for JSON APIs.
The tool builds exactly that minimal, correct request. From there, real-world requests usually grow — authentication headers (Authorization: Bearer ...), request bodies (-d), and query parameters. The generated command is the clean starting point you extend with your specifics.
One note on accuracy: the command is assembled from what you type, so an incorrect URL or method produces an incorrect request. The tool's job is formatting, not validating your endpoint.
Privacy & security
Your data stays yours
Your commands are generated entirely in your browser. Nothing is uploaded or stored.
Local processing — files stay in your browser
- Command assembly runs locally — your endpoints are not transmitted.
- Nothing is retained after you close the tab.
- The command is copied directly from your browser.
- Analytics only record the page visit.
Limitations
What this tool does not do
- Generates curl commands — it does not execute requests itself.
- Only the URL and method are captured; headers and bodies must be added manually.
- The endpoint and method are not validated for correctness.
- For live request testing, use a dedicated API client.
Frequently asked questions
Common questions about API Tester
Does this tool send requests?
No. The tool generates a curl command for you to run in your terminal. It never sends a request itself — your endpoints are never contacted from this page.
Can I add headers and request bodies?
The generated command includes a JSON content-type header as a starting point. Add authorization headers, bodies, and query parameters to the command before running it.
Which HTTP methods are supported?
Any method you type — GET, POST, PUT, PATCH, DELETE, and others — is passed through into the generated command.
Why is curl useful for API testing?
curl is installed on virtually every system, works from scripts and CI, and makes requests reproducible — the same command produces the same request every time.
Is my endpoint private?
Yes. The command is generated locally in your browser and your endpoint is never sent anywhere.
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